Batman #415 1987

Batman #415, a Millennium Week Two tie-in from DC Comics, sees Batman and Robin (Jason Todd) infiltrate Arkham Asylum. Batman suspects Commissioner Gordon is a Manhunter impostor attempting to kill the Floronic Man. Robin disobeys orders, defeating Scarecrow with his own fear gas, which Batman then uses to create a disguise for their Arkham entry. This issue is notable for its direct connection to the Millennium crossover event and features a rare instance of Batman utilizing a villain's weapon against other inmates, including a Joker cameo.